A +2.00-nC point charge is at the origin, and a second -5.00-nC point charge

A +2.00-nC point charge is at the origin, and a second -5.00-nC point charge is on the x-axis at x = 0.800 m.

(a) Find the electric field (magnitude and direction) at each of the following points on the x-axis:
(i) x = 0.200 m;
(ii) x = 1.20 m;
(iii) x = -0.200 m.
(b) Find the net electric force that the two charges would exert on an electron placed at each point in part (a).

This video explains it! https://youtu.be/NZe1L3Uhrsc